Cordelia Fine (author of the highly recommended Delusions of Gender), has written a response to the latest Brain Sex! research to have hit the mainstream press last month (I wrote about it at the time here), below is one of the highlights:
In an larger earlier study (from which the participants of the PNAS study were a subset), the same research team compellingly demonstrated that the sex differences in the psychological skills they measured – executive control, memory, reasoning, spatial processing, sensorimotor skills, and social cognition – are almost all trivially small.
To give a sense of the huge overlap in behaviour between males and females, of the twenty-six possible comparisons, eleven sex differences were either non-existent, or so small that if you were to select a boy and girl at random and compare their scores on a task, the “right” sex would be superior less than 53% of the time.
Even the much-vaunted female advantage in social cognition, and male advantage in spatial processing, was so modest that a randomly chosen boy would outscore a randomly chosen girl on social cognition – and the girl would outscore the boy on spatial processing – over 40% of the time.
As for map-reading and remembering conversations, these weren’t measured at all.
Yet the authors describe these differences as “pronounced” and as reflecting “behavioural complementarity” – scientific jargon-speak for “men are from Mars, women are from Venus”. Rather than drawing on their impressively rich data-set to empirically test questions about how brain connectivity characteristics relate to behaviour, the authors instead offer untested stereotype-based speculation. Even though, with such considerable overlap in male/female distributions, biological sex is a dismal guide to psychological ability.
Please read the rest of the article, where Fine discusses experience-dependent brain plasticity, and how the differences in connectivity between male and female brains “may reflect the different wiring solutions of larger versus smaller brains, rather than sex differences per se.”